packet_mmap: expose hw packet timestamps to network packet capture utilities (614f60fa) · Commits · 戴 / test

Documentation/networking/packet_mmap.txt

+26 −0

Original line number	Original line	Diff line number	Diff line
	@@ -493,6 +493,32 @@ The user can also use poll() to check if a buffer is available:
	pfd.events = POLLOUT;		pfd.events = POLLOUT;
	retval = poll(&pfd, 1, timeout);		retval = poll(&pfd, 1, timeout);

			-------------------------------------------------------------------------------
			+ PACKET_TIMESTAMP
			-------------------------------------------------------------------------------

			The PACKET_TIMESTAMP setting determines the source of the timestamp in
			the packet meta information. If your NIC is capable of timestamping
			packets in hardware, you can request those hardware timestamps to used.
			Note: you may need to enable the generation of hardware timestamps with
			SIOCSHWTSTAMP.

			PACKET_TIMESTAMP accepts the same integer bit field as
			SO_TIMESTAMPING. However, only the SOF_TIMESTAMPING_SYS_HARDWARE
			and SOF_TIMESTAMPING_RAW_HARDWARE values are recognized by
			PACKET_TIMESTAMP. SOF_TIMESTAMPING_SYS_HARDWARE takes precedence over
			SOF_TIMESTAMPING_RAW_HARDWARE if both bits are set.

			int req = 0;
			req \|= SOF_TIMESTAMPING_SYS_HARDWARE;
			setsockopt(fd, SOL_PACKET, PACKET_TIMESTAMP, (void *) &req, sizeof(req))

			If PACKET_TIMESTAMP is not set, a software timestamp generated inside
			the networking stack is used (the behavior before this setting was added).

			See include/linux/net_tstamp.h and Documentation/networking/timestamping
			for more information on hardware timestamps.

	--------------------------------------------------------------------------------		--------------------------------------------------------------------------------
	+ THANKS		+ THANKS
	--------------------------------------------------------------------------------		--------------------------------------------------------------------------------

include/linux/if_packet.h

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -48,6 +48,7 @@ struct sockaddr_ll {
	#define PACKET_LOSS 14		#define PACKET_LOSS 14
	#define PACKET_VNET_HDR 15		#define PACKET_VNET_HDR 15
	#define PACKET_TX_TIMESTAMP 16		#define PACKET_TX_TIMESTAMP 16
			#define PACKET_TIMESTAMP 17

	struct tpacket_stats {		struct tpacket_stats {
	unsigned int tp_packets;		unsigned int tp_packets;

net/packet/af_packet.c

+35 −2

Original line number	Original line	Diff line number	Diff line
	@@ -83,6 +83,7 @@
	#include <linux/if_vlan.h>		#include <linux/if_vlan.h>
	#include <linux/virtio_net.h>		#include <linux/virtio_net.h>
	#include <linux/errqueue.h>		#include <linux/errqueue.h>
			#include <linux/net_tstamp.h>

	#ifdef CONFIG_INET		#ifdef CONFIG_INET
	#include <net/inet_common.h>		#include <net/inet_common.h>
	@@ -202,6 +203,7 @@ struct packet_sock {
	unsigned int tp_hdrlen;		unsigned int tp_hdrlen;
	unsigned int tp_reserve;		unsigned int tp_reserve;
	unsigned int tp_loss:1;		unsigned int tp_loss:1;
			unsigned int tp_tstamp;
	struct packet_type prot_hook ____cacheline_aligned_in_smp;		struct packet_type prot_hook ____cacheline_aligned_in_smp;
	};		};

	@@ -656,6 +658,7 @@ static int tpacket_rcv(struct sk_buff skb, struct net_device dev,
	struct sk_buff *copy_skb = NULL;		struct sk_buff *copy_skb = NULL;
	struct timeval tv;		struct timeval tv;
	struct timespec ts;		struct timespec ts;
			struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);

	if (skb->pkt_type == PACKET_LOOPBACK)		if (skb->pkt_type == PACKET_LOOPBACK)
	goto drop;		goto drop;
	@@ -737,7 +740,13 @@ static int tpacket_rcv(struct sk_buff skb, struct net_device dev,
	h.h1->tp_snaplen = snaplen;		h.h1->tp_snaplen = snaplen;
	h.h1->tp_mac = macoff;		h.h1->tp_mac = macoff;
	h.h1->tp_net = netoff;		h.h1->tp_net = netoff;
	if (skb->tstamp.tv64)		if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
			&& shhwtstamps->syststamp.tv64)
			tv = ktime_to_timeval(shhwtstamps->syststamp);
			else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
			&& shhwtstamps->hwtstamp.tv64)
			tv = ktime_to_timeval(shhwtstamps->hwtstamp);
			else if (skb->tstamp.tv64)
	tv = ktime_to_timeval(skb->tstamp);		tv = ktime_to_timeval(skb->tstamp);
	else		else
	do_gettimeofday(&tv);		do_gettimeofday(&tv);
	@@ -750,7 +759,13 @@ static int tpacket_rcv(struct sk_buff skb, struct net_device dev,
	h.h2->tp_snaplen = snaplen;		h.h2->tp_snaplen = snaplen;
	h.h2->tp_mac = macoff;		h.h2->tp_mac = macoff;
	h.h2->tp_net = netoff;		h.h2->tp_net = netoff;
	if (skb->tstamp.tv64)		if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
			&& shhwtstamps->syststamp.tv64)
			ts = ktime_to_timespec(shhwtstamps->syststamp);
			else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
			&& shhwtstamps->hwtstamp.tv64)
			ts = ktime_to_timespec(shhwtstamps->hwtstamp);
			else if (skb->tstamp.tv64)
	ts = ktime_to_timespec(skb->tstamp);		ts = ktime_to_timespec(skb->tstamp);
	else		else
	getnstimeofday(&ts);		getnstimeofday(&ts);
	@@ -2027,6 +2042,18 @@ packet_setsockopt(struct socket sock, int level, int optname, char __user optv
	po->has_vnet_hdr = !!val;		po->has_vnet_hdr = !!val;
	return 0;		return 0;
	}		}
			case PACKET_TIMESTAMP:
			{
			int val;

			if (optlen != sizeof(val))
			return -EINVAL;
			if (copy_from_user(&val, optval, sizeof(val)))
			return -EFAULT;

			po->tp_tstamp = val;
			return 0;
			}
	default:		default:
	return -ENOPROTOOPT;		return -ENOPROTOOPT;
	}		}
	@@ -2119,6 +2146,12 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
	val = po->tp_loss;		val = po->tp_loss;
	data = &val;		data = &val;
	break;		break;
			case PACKET_TIMESTAMP:
			if (len > sizeof(int))
			len = sizeof(int);
			val = po->tp_tstamp;
			data = &val;
			break;
	default:		default:
	return -ENOPROTOOPT;		return -ENOPROTOOPT;
	}		}

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